Instrument for the withdrawal of body fluids

ABSTRACT

An improved syringe for the withdrawal of body fluids, especially adapted for transport and storage as well as for the centrifugation of the fluid samples, preferably blood samples, comprises a tube having a hermetically end, the closure of which, being a stopper or cap, is entirely or partly made of resilient material, through which a needle, preferably of stainless steel, extends, which ends in or is tightly pressured against a piston mounted in the tube. Said piston is preferably provided with a concave at the side where the needle ends. Thus a hermetically sealed compartment is obtained through which the needle extends. Said Compartment is suitable for aseptic storage of auxiliaries such as anticoagulants and/or antiseptics.

[ Feb. 29, 1972 United States Patent Goverde et al.

...l28/2l6 X Lockhart...............................l28/216Sarnoff...............................

i ebfl 5 eha KCL 48574 66645 99999 lllll 1 0111 11 43363 00 08 ,J 660 326039 33322 Primary Examiner-Hugh R. Chamblee Att0meyHugo E. Weisberger[22] Filed: Nov. 4, 1969 ABSTRACT [21] Appl. No.:

the withdrawal of body fluids, espe- An improved syringe for ciallyadapted for transport and storage as well as for the cen- [30] ForelgnApplication Priomy Dam trifugation of the fluid samples, preferablyblood samples,

ff 00 6.: r mm mm y m a P u r. 0 y We 3 cu Ue ms mm c r g0 HT .1 WW m msua t m 8 6 Rb mh 6 mi. h CW 1 2 l 6 1 co S d n a n e h t e N 8 6 9 2 lV. 0 N

ured against a piston mounted in the tube. Said piston is preferablypro- 128/; F, 123/276 resilient material, through which a needle,preferably of stain- Amb 10/00 less steel, extends, which ends in or istightly press 128/2 F, 2 G; 73/4256 vided with a concave at the sidewhere the needle ends. Thus a hermetically sealed compartment isobtained through which Field ofSearch...................l

I C t H I ll] 00 55 [i References Cited the needle extends. SaidCompartment is suitable for aseptic storage of auxiliaries such asanticoagulants and/or antisepti UN lTED STATES PATENTS 3,162,195 Dick.....................................128/216 7Claims,3Drawing FiguresINSTRUMENT FOR THE WIT HDRAWAL OF lBOlDY FLUIDS BACKGROUND OF THEINVENTION An instrument which is frequently applied for drawing bodyfluids more particularly blood, is a hypodermic syringe. When thissyringe is not used for injection purposes, but for taking samples of abody fluid, this fluid after the puncture has to be transferred into acontainer in order to transport said fluid or to performclinical-chemical determinations in it. The drawbacks of such a methodare obvious as these operations take much time and the chance ofmistakes is increased. Moreover, after the use the syringe has to becleaned and, if necessary or desired, sterilized again and provided withfresh anticoagulants and/or antiseptics.

Of the hypodermic syringes which have been developed so far for thewithdrawal of body fluids no variants are known which are also suitablefor the storage, the transport and the centrifugation of these fluids.

Since there is at present a strong tendency towards greater efficiencyand, connected therewith, greater uniformity of apparatuses to be usedin clinical-chemical determinations, the need is felt of a fluid drawinginstrument which is also equipped for the transport, the storage and thecentrifugation of the fluid.

A partial, but by no means ideal solution of the above-mentionedproblems was found in the use of an apparatus comprising the followingtwo essential parts:

1 a vacuum ampoule fitted at one side with a cap or stopper of resilientmaterial;

2. a holder with a needle pointed at both ends in which the vacuumampoule can be placed.

By means of such an apparatus blood can be taken by inserting the needleinto a blood vessel and then exerting pressure on the ampoule so thatthe needle will pierce the resilient cap of the ampoule. However, such adevice is rather expensive, due to the fact that special vacuum ampoulesare required. Another great objection is that the movement which has tobe made to withdraw the fluid (exerting such a pressure on the vacuumampoule that the needle will pierce the cap of the ampoule) isessentially contrary to the movement made when an ordinary hypodermicsyringe is used. Moreover, so much pressure should be exerted that thereis a danger of the needle piercing the vein, which can give rise tohematomae and other injuries. Besides the ampoule cannot be filled upcompletely there will always remain a certain space above the bloodcontaining air or another gas, in consequence of which undesired changesmay occur during the transport of the blood.

SUMMARY OF THE INVENTION An instrument has now been found adapted to beemployed for the withdrawal of body fluids. This instrument is alsosuitable for the transport and the storage of these fluids, as well asfor the centrifugation and other preparatory operations prior to theperformance of clinical-chemical determinations, to which instrument nosuch drawbacks as those mentioned above are attached. It can beconstructed at such a low cost that after a single use the instrumentcan be discarded.

The instrument according to the invention is characterized by a tubehaving one hermetically closed end, the closure of which is entirely orpartly made of resilient material, through which material a needleextends which ends in a piston mounted in the tube, which piston isfitted with a device which enables said piston to be moved.

DESCRIPTION OF THE PREFERRED EMBODIMENT The instrument according to theinvention is illustrated in FIG. I in the sheet of drawings,representing one of the possible embodiments of the invention.

The process of taking body-fluids with such a device is very simple. Theneedle is inserted into the body in the conventional manner, after whichthe fluid is withdrawn by moving the piston backwards. After thepuncture the detachable parts of the instrument, including the needle,are removed, after which the body of the instrument, a handy tube,containing a hermetically sealed quantity of fluid, remains. If aspecimen of blood has been taken which is to be transported over longdistances, for instance, by airmail, the air has to be removed from thetube, because, due to excessive shaking during the transport, hemolysismay be caused. For this purpose the needle is not immediately entirelyremoved from the tube, but only in part, so that the end of the needlejust remains in communication with a concave which should preferably bemade in the closure. By moving the piston towards the needle whilekeeping the tube in a vertical position, the air first collects in theconcave, after which it is removed through the needle. Then the needlecan be entirely drawn from the closure.

Now, the tube containing the fluid (FIG. lIl) can be stored ortransported and, if desired, centrifuged to separate any solid substancefrom the fluid.

The parts of the instrument according to the invention are illustratedfurther with reference to FIG. I in the sheet of drawings.

The tube (1 e.g., of cylindrical shape, should preferably be made oftransparent material. Tubes made of synthetic material, such for exampleas polystyrene, acrylstyrene, polypropylene and polymethylpentene orother polyolefins, are very suitable for this purpose. The dimensionsand the content of the tube depend, of course, on the purpose for whichthe instrument according to the invention is used, but it is aprerequisite that the tube should be adapted to be used in the commonlaboratory centrifuges. For the performance of most clinical-chemicaldeterminations in the blood of adults a blood sample of 10 ml. issufficient.

At one end the tube is hermetically closed, for example with a cap or astopper partly or entirely made of resilient material, for example,rubber. There should preferably be a concave (3) in the closurecommunicating with the interior of the tube, which permits any airpresent in the tube to be removed easily, as described above. The needle(4) which should be made of durable material, preferably stainlesssteel, extends through the resilient part of the closure eithercentrically or eccentrically according to the location of the concave.Moreover, the needle should preferably be fitted with a guard (5)preventing the needle from penetrating further into the tube.

The end of the needle which is in the tube should end in or tightlypress against a piston (7). Preferably the needle reaches to theinterior of the piston so that on injection it can no more movesidelong. Hence a needle which is pointed at both ends is the mostsuitable needle to employ in the instrument according to the invention.Thus a perfectly hermetically sealed compartment (6) is obtained,through which the needle extends either centrically or eccentrically.

In the piston there should preferably be a concave at the side where theneedle ends, which offers advantages on examination of the sedimentobtained after centrifuging, which has collected in the concave. Also,the piston is fitted with, or can be fitted with a device for moving it.For this purpose a piston rod is mostly used. With a view tocentrifuging the fluid, the piston rod should be detachable annexed, inany case that part which sticks out of the tube after withdrawal of thefluid. To fulfill this requirement the piston rod can be provided with,for example, a breaking point. However, it is to be preferred to providethe piston with a device (8), for example a screw thread or a catch, tofasten a loose piston rod, but other devices, too, can be used in theinstrument according to the invention to move the piston.

The other open end of the tube can be closed with a cap (9), which canbe provided with an opening, if desired, through which quite easily apiston rod can be put. For special purposes said opening is closed by afilm, for example, of rubber or plastic (10). Such a closure is requiredif microbiological determinations are to be performed in connection withwhich not only compartment (6), but the whole inner side of the tubeshould be sterile.

The part of the needle extending out of the tube can be protected with acover, which serves a double purpose: it protects the needle and keepsit sterile. The material of which said cover is made should preferablybe pervious to sterilizing gases such as ethylene-oxide.

The device according to the invention can be supplied perfectly sterileand is constructed in such a way that the sterility will be maintainedfor a virtually unlimited time.

To the instrument according to the invention, which is illustrated inFIG. I in the sheet of drawings and which is one of the possibleembodiments of the invention, belongs a loose piston rod, which must bemounted on the piston before use. Such a piston rod (FIG. II) can bemade of durable material, for example stainless steel. If the sterilityshould be extremely great on taking the fluid, the piston rod can besterilized before it is fitted in the tube, for example, by flaming.

The fluid-withdrawal instrument according to the invention is destroyedor discarded after use; a piston rod of durable material can be usedover and over again. However, the piston rod can also be made ofsynthetic material, in which case it is discarded together with thefluid-withdrawal instrument after one-time use. If sterility isrequired, such a loose piston rod of synthetic material can bemanufactured in a sterilized package.

In practice most determinations have been performed in blood serum sofar, that is to say, in the fluid that remains after clotting has takenplace. The instrument according to the invention enables this serum tobe prepared a short time after the puncture and free from hemolysis.

However, a number of determinations in blood are performed starting fromwhole blood or blood plasma, that is to say, starting from blood whichhas not been allowed to clot.

Examples of such determinations are: the determination of amino acids,amino-nitrogen, ascorbic acid, lactic acid and al cohol, and further,for example, the hematocrite value, the oxygen-binding capacity, theprothrombin time and the erythrocyte-sedimentation time.

Dependent on the determinations to be performed in blood, the followinganticoagulants are often used: sequestering agents such as salts ofethylenediamine-tetraacetic acid, for example, potassium or sodium EDTA,heparin, for example, potassium, sodium or lithium salts, sodiumfluoride, sodium citrate, potassium or sodium oxalate orpotassium-ammonium oxalate.

Said coagulants, in a solid or in a liquid form, can be passedaseptically into the sterilized device according to the invention, andthat into the compartment (6) between the piston and the closure. As theneedle presses tightly against or reaches to the interior of the piston,said substances cannot penetrate into the needle so that they cannotconstitute a danger to the patient or block up the needle. Theinstruments according to the invention filled with different coagulantsshould be clearly distinguishable from each other, for example, by aclear code and/or differences in color.

The following four types of blood withdrawal instruments are suitablefor most clinical-chemical determinations:

l. blood-withdrawal instrument having an empty sterile space betweenstopper and piston;

2. blood-withdrawal instruments having a sequestering agent in thecompartment in question, for example, tripotassium EDTA;

3. blood-withdrawal instrument containing heparin in the form of thesodium salt;

4. blood-withdrawal instrument containing sodium citrate.

For determinations to be performed in body fluids other than blood, suchas lumber fluid, interarticular fluid and pleural fluid, otherauxiliaries such as antiseptics, can be present in the instrumentaccording to the invention. It stands to reason that the nature of thedetermination to be performed plays a part in the choice of theauxiliary. Likewise the diameter and the length of the needle must beadapted to the field of application.

It is claimed: 1. An instrument for the withdrawal of body fluidscomprising a tube having an open end and a hermetically closed oppositeend, the interior of said tube being at substantially atmosphericpressure, a closure member at the closed end of the tube providing saidhermetic seal which is at least partly made of resilient materialthrough which material a hollow needle extends which terminates in andis sealed by a piston slidably mounted in the interior of said tubeprovide a hermetically sealed compartment between said closure memberand said piston, said compartment being penetrated by said needle, saidpiston being provided with means for moving the piston away from theclosed end of the tube.

2. The instrument of claim 1, in which said closure has a concavecommunicating with the interior of the tube.

3. The instrument of claim 1, in which said piston possesses a concaveportion at the side where the needle terminates in the piston.

4. The instrument of claim 1, in which said piston is fitted with meansfor fastening a piston rod.

5. The instrument of claim I, in which the open end of said tube isclosed with a cap fitted in the middle with a film which can easily bepenetrated by a piston rod.

6. The instrument of claim 1 which includes a piston rod attached tosaid piston.

7. The instrument of claim 1 in which said needle is provided with aguard to prevent further penetration into said tube.

1. An instrument for the withdrawal of body fluids comprising a tubehaving an open end and a hermetically closed opposite end, the interiorof said tube being at substantially atmospheric pressure, a closuremember at the closed end of the tube providing said hermetic seal whichis at least partly made of resilient material through which material ahollow needle extends which terminates in and is sealed by a pistonslidably mounted in the interior of said tube provide a hermeticallysealed compartment between said closure member and said piston, saidcompartment being penetrated by said needle, said piston being providedwith means for moving the piston away from the closed end of the tube.2. The instrument of claim 1, in which said closure has a concavecommunicating with the interior of the tube.
 3. The instrument of claim1, in which said piston possesses a concave portion at the side wherethe needle terminates in the piston.
 4. The instrument of claim 1, inwhich said piston is fitted with means for fastening a piston rod. 5.The instrument of claim 1, in which the open end of said tube is closedwith a cap fitted in the middle with a film which can easily bepenetrated by a piston rod.
 6. The instrument of claim 1 which includesa piston rod attached to said piston.
 7. The instrument of claim 1 inwhich said needle is provided with a guard to prevent furtherpenetration into said tube.